Field of the Invention and Related Prior Art
The present invention relates to a method and a device of inserting an electric heating wire into a hot water tube and a sealing apparatus for the open end thereof.
Traditional hot water tube for domestic floor heating posed little problem for installation in case of a boiler-equipped system, but the lengthiness and zig-zag layout of the pipe line would cause a difficulty in inserting a coated electric heating wire into a hot water tube in a system where warming of floor is realized by heating a thermal medium within the tube without using a boiler.
A number of means have been known to tackle this problem, and in the case of a prior art related to the present invention, a utility model by the same applicant of the present application registered under the Korean Utility Model Registration No. 20-0148379, a coated copper wire was inserted into a hot water tube from an adapter directly connected to the hot water tube and the coated copper wire was pulled into and carried along inside the tube as a guiding plate attached with the coated copper wire was forced to move forward along the entire length inside the tube line by the pressure of water being supplied from a pump provided at a side of the adapter.
In this prior art, a plural number of funnel-shaped guiding plates were used so that the guiding plates may move under the water pressure, pulling along the coated copper wire toward the other end of the tube. But, the gap between the funnel-shaped guiding plate and the inner wall of the tube would increase depending on the position of the guiding plates in transit, resulting not only in a leakage of water pressure through the gaps and consequent poor utility rate of water pressure but also in frequent pauses of the coated copper wire movement somewhere inside the tube owing to a blocking at the bents (or curves) of the tube line. When the guiding plate came to a halt in the middle of its travel, it used to pose a complex situation in which water pressure supply had to be turned off and the coated copper wire already in the tube had to be retrieved to repeat the insertion process from the beginning.
The present invention is an improvement of said prior art. A sealing plug of the present invention is the core of a sealing apparatus through which an electric heating wire is inserted. This sealing plug is an improvement from the prior art by the same applicant of the present invention, Korean Utility Model Registration No. 20-0172037 (published 15 Mar. 2000), of the construction of a sealing apparatus for the end(s) of a hot water tube into which an electric heating wire is inserted.
In said prior art, a sealing plug is fitted into each end of the hot water tube in which a coated electric heating wire is inserted along the inside of the entire length of the tube, wherein the sealing plug in which a coated electric heating wire passes is attached to each end of the hot water tube, a cylinder-type cap is fastened, and a crown nut is tightened to press the sealing plug against the inner surface of the tube to tightly seal the open end of the hot water tube.
The sealing effect of the apparatus of the prior art above is proven to be better than that of the previous art in that the tube ends are sealed preventing the hot water, the heating medium, from leaking outside in a condition in which a part of the coated electric heating wire extends out of the tube, without the use of an adhesive for bonding to achieve a sealing effect.
However, as the coated electric heating wire protruding from the hot water tube is thin and weak compared to the power line, it is susceptible to damage during a heating system installation. Safety of the sealing device is further affected under the condition where a coated electric heating wire and a power line are jointed together outside the tube, where a hot water tube is fixed to a wall or a floor, or where if it is rubbed or scraped against a hole on the crown nut fixed at the end of the hot water tube or pulled hard.
These problems are common challenges that have to be tackled with the prior arts.